If your mobile phone didn’t work, or dropped out during a call in Sydney this week, it could be because of the sudden influx of overseas visitors for the APEC summit, the federal Attorney-General’s department admitted yesterday, reported The Sydney Morning Herald (6/9/2007, p. 9).Official silence on security: “Mobile calls can fail for a number of reasons related to both the handset and the network, including congestion,” the department said. “Significant congestion of mobile networks is likely during the APEC leaders’ week and particularly around the APEC area in the Sydney CBD.” The department refused to comment on security measures that could block mobile coverage in certain areas. Telstra said such jamming devices existed but refused to comment further. “There are devices that are available to security to dampen localised areas and you’d have to talk to the police about that sort of thing,” a Telstra spokesman, Jeremy Mitchell, said.